Ok man ang jiu jitsu bro, if one-on-one combat ra. Pero if multiple opponents, the best thing for a BJJ practitioner to do is run. Mas okay pod nga naa kay background in striking martial arts together with BJJ, para dali ra nimo ma tackle, take down, and lock ang imong opponent. Also in Aikido and Judo, if malipong or ma bun-og na imong kontra, dali nalang siya e clip iyang arms.
But there are times when a situation arrives that running is not the best option. I agree on what you said about resorting to dirty tactics. Dirty tactics is like a bamboo stick used for hitting, but with adequate training in offensive martial arts, that bamboo can be sharpened into a spear. And with further mastery, that bamboo spear can be tipped with poison.
Aside from that, in the lighter side of life... the more rigid the Martial Arts is, the more we are exposed to an extreme work-out, good for our health.

And it really feels good whenever you release your stress on the punching bag or during your sparring sessions. There are lots of different exercises out there, and undergoing training in yawyan or muay thai is one of the best things to lose weight, reduce cholesterol and increase mental alertness.
It really depends on the person which is his/her preference.